import java.util.*;
public class Main2
{
    public static void main(String[] args)
    {
        Scanner cin = new Scanner(System.in);

        double x = cin.nextDouble();
        if(x<1)
        {
            System.out.printf("%.2f",Math.abs(x));
        }
        else if(x>=1&&x<10)
        {
            System.out.printf("%.2f",Math.pow(x,3.6));
        }
        else
        {
            System.out.printf("%.2f",Math.sqrt(x));
        }
        cin.close();
    }
}
